Zoeken

This is the second in a two-part tutorial on the collection of antenna data and how to create customized antenna patterns using Ekahau. The first tutorial focused on methods for adding an antenna to an access point (AP).

The focus of this article is to customize a new antenna for WiFi and Bluetooth. In some cases, you might be able to find a vendor to supply you with the antenna data you need. However, if that is not the case, these instructions are a workaround for that.



Let's say we want to add this 5Ghz antenna pattern, and the antenna has a maximum gain of 5dBi. The antenna scale starts at 0dBi, and this also reflects the maximum gain of 5dBI. It is important to know that Ekahau does not start at 0, but at maximum gain.


For example, a measurement of:

· 0dbi is in fact 5dBi,

· -1dBi is in fact 4dBi

· -2dBi is in fact 3dBi

· -3dBi is in fact 2dBi

· -4dBi is in fact 1dBi

and so on.


In this case, we are going to start with 0 degrees on top, and go clockwise in increments of 5 degrees. This means that each step in is -5dBi. Take note that this vertical pattern is rotated 90 degrees relative to the horizontal pattern.


We can use Ekahau to add reasonably accurate data through the antenna pattern as a map. This map is scaled at 50 meters for an inward step for easy calculation. Assuming this, we can say that every 50 meters equals 5dBi. For example, a measurement of 84.1 meters equals -8.41dBi.


We can now measure from the outer 0dBi ring inwards to the center of the red stripe, you do this for every 5 degrees.


In this case, we measure:

0 degrees 84.1 meters equal to -8.41dBi + 5dBi (maximum antenna gain) = -3.41dBi

5 degrees 77.3 meters equal to -7.73dBi + 5dBi = -2.73dBi

10 degrees 6.26 meters equal to -6.26dBi + 5dBi = --1.26dBi

The accuracy of your measurement points depends on you. This might not be the fastest or the best way to do it, but it works. I found an error in an existing antenna that reads -18dBi different from the datasheet using this method. Ekahau confirmed this and solved it in an update.



let's talk code


To add or modify antenna patterns in Ekahau, navigate to the configuration folder (e.g. C:\Program Files\Ekahau\ Ekahau Pro\conf\). Look for and open antennas.zip.

Here you will find all the antennas in Ekahua. Add the new antenna in this zip file.

The code in these files will look something like this:


{ 
 "directional": true,  
 "horizontalPlane": {  
 "alignment": {  
 "degrees": 0.0 
    },  
 "gains": [  
      { 
 "angleInDegrees": 0.0,  
 "dBi":  -3.41
      },  
      { 
 "angleInDegrees": 5.0,  
 "dBi":  -2.73
      },  
      { 
ect.
 } 
    ],  
"type": "Azimuth",  
 "scaleMin": -25.0,  
 "scaleMax": 5.0 
  },  
 
 "elevationPlane": { 
 "alignment": {  
 "degrees": 90.0 
    },  
 "gains": [  
      { 
 "angleInDegrees": 0.0,  
 "dBi":  -2.78
      },  
      { 
 "angleInDegrees": 5.0,  
 "dBi":  -2.60
      },  
      { 
ect.
   } 
    ],  
 "type":   "Elevation",
 "scaleMin": -25.0,
 "scaleMax": 5.0
  },
 "frequencyBand": "FIVE",
 "accessPointVendorModel": {
 "vendor": {
 "vendor": "Custum"
    },
 "model": {
 "model": "Antenna 001"
    }
  },
 "wcsMapping": {},
 "defaultTiltAngle": {
 "degrees": 0.0
  },
 "manufacturerMaximumGain": 5.0,
 "antennaTechnology": "WIFI",
 "defaultMounting": "WALL",
 "apCoupling": "EXTERNAL_ANTENNA"
} 

Definitions of some code terms

 "directional":

True for directrional antennas, False for Omni antennas.


 "alignment": {
 "degrees": 0.0
    },

Alignment offset in degrees from 0 to 360.

You can also exclude some alignment offset in degrees in this manner "alignment": {}









 "angleInDegrees": 

Increments in degrees of difference from 0 to 360, for example, 0. 5, 10, 15, and so on.


"dBi": 3.41

Describes the dBi value at a certain degree of the antenna pattern.


 "scaleMin":-25.0,
 "scaleMax": 5.0

Describes the minimum and maximum scale of the antenna pattern, which can also be entered as NaN.


frequencyBand": 

TWO for 2,4GHz, FIVE for 5GHz in double quotes and continued with a comma.


 "accessPointVendorModel": {
 "vendor": {
 "vendor": "Costum Antenna"
    },
 "model": {
 "model": "Custom Antenna 001"

Name the vendor and model in double quotes


 "defaultTiltAngle": {
 "degrees":
  },

Tilt angle in degrees from 0 to 360.










"manufacturerMaximumGain": 

Maximum gain described in the antenna datasheet, or NaN continued with a comma.


"antennaTechnology": 

"BLUETOOTH", "WIFI" in double quotes and continued with a comma.


 "defaultMounting": 

"WALL" or "CEILING" in double quotes and continued with a comma.


"apCoupling": 

"INTERNAL_ANTENNA" or"EXTERNAL_ANTENNA"



After you have modified or created the code, you can save it in the zip file under the name of the antenna with a .json extension.You can now use this antenna in Ekahau.


If you have created an internal antenna, you need to take an extra step:

Navigate to the configuration folder (e.g. C:\Program Files\Ekahau\ Ekahau Pro\conf\). Look for and open accessPointsTypes.xml with admin rights (right-click on the file and choose “Run as administrator”).

Add this piece of script and change the red highlighted data using the datasheet of your selected AP, then add your antenna in the script, like so:


  </accessPointType>
  <accessPointType vendor="Custum" model="Custum Antenna 001">
    <radioType technology="n" frequencyBand="2.4" mimo="2x2" spatialStreams="2" defaultAntenna24="Custum Antenna 001 2.4GHz" defaultAntenna5="Custum Antenna 001 5GHz"/>
    <radioType technology="ac" frequencyBand="5" mimo="3x3" spatialStreams="3" maxSupportedBandwidth="160MHz" defaultAntenna24="Custum Antenna 001 2.4GHz" defaultAntenna5="Custum Antenna 001 5GHz"/>

more about custom AP and antenna combinations at https://www.wireless-blog.com/post/custom-ap-antenna-combination-in-ekahau



Note

with an incorrect code it can happen that ekahau no longer starts up or that the edit Access Point no longer works, this can usually be solved by removing your antenna from the zip file.

Also backup the files as well,this will be rewritten with the next update.




Are you working on a design in Ekahau Site Survey (ESS) and using a specific AP (Access Point) with different antenna types? In my case, in my existing project file, I had to change all the Access Points to a new type. I made the choice for Aruba 504 + AP-ANT-25A - this is not a direct combination in Ekahau but with a detour. When you assign an AP in ESS, the next time you add a new AP to the map, it uses the earlier AP you had placed.

However, if you customize an Access Point by choosing an AP from the drop-down and changing the antennas to a 3rd party antenna – the next time you want to change it, this is only possible by choosing an ap from the drop down menu. This is a disadvantage if you’re adding plenty of APs, and/or b) switching between various antenna types.

Each time you place an AP, you have to manually go in and make changes to everything - the angles, antenna height, TX power, and - the antennas themselves. You can make changes to the ESS config files for adding APs and custom antennas.

When you edit the “accessPointTypes.xml” file and add the AP with the antennas you want, the antenna might already exist in ESS but it might not be paired with the AP you want to use. This is all you need to fix to make it work.

After fixing it, if you open your project file in ESS, you can see the new customized version of the AP in the list!

Creating Access Points in Ekahau

The following are the steps to create access points yourself in Ekahau:

Step 1

Open C: \ Program Files \ Ekahau \ Ekahau Pro \ conf \

Now, open antennas.zip. copy here from the filename without extension.


You can find both the 2.4GHz and 5GHz antennas you need.






Step 2

Open C: \ Program Files \ Ekahau \ Ekahau Pro \ conf \. Then, open accessPointsTypes.xml with admin rights.

Step 3

Search for your required AP and find it. Next, copy it.


 </accessPointType>
 <accessPointType vendor="Aruba" model="AP-504 + AP-ANT-1W">
 <radioType technology="ax" frequencyBand="2.4" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
 <radioType technology="ax" frequencyBand="5" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
  <radioType radioTechnology="bluetooth" frequencyBand="2.4" defaultAntennaBluetooth="Aruba AP-505 BLE"/>

Paste the AP directly under the original AP.


</accessPointType>
 <accessPointType vendor="Aruba" model="AP-504 + AP-ANT-1W">
 <radioType technology="ax" frequencyBand="2.4" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
 <radioType technology="ax" frequencyBand="5" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
  <radioType radioTechnology="bluetooth" frequencyBand="2.4" defaultAntennaBluetooth="Aruba AP-505 BLE"/>
</accessPointType>
 <accessPointType vendor="Aruba" model="AP-504 + AP-ANT-1W">
 <radioType technology="ax" frequencyBand="2.4" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
 <radioType technology="ax" frequencyBand="5" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
  <radioType radioTechnology="bluetooth" frequencyBand="2.4" defaultAntennaBluetooth="Aruba AP-505 BLE"/>

Step 4

Change the red highlighted data using the previously selected AP from step 1.


 </accessPointType>
 <accessPointType vendor="Aruba" model="AP-504 + AP-ANT-1W">
 <radioType technology="ax" frequencyBand="2.4" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
 <radioType technology="ax" frequencyBand="5" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
  <radioType radioTechnology="bluetooth" frequencyBand="2.4" defaultAntennaBluetooth="Aruba AP-505 BLE"/>
</accessPointType>
 <accessPointType vendor="Aruba" model="AP-504 + AP-ANT-1W">
 <radioType technology="ax" frequencyBand="2.4" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
 <radioType technology="ax" frequencyBand="5" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-1W 2.4GHz" defaultAntenna5="Aruba AP-ANT-1W 5GHz"/>
  <radioType radioTechnology="bluetooth" frequencyBand="2.4" defaultAntennaBluetooth="Aruba AP-505 BLE"/>

The below will get displayed in my case.


</accessPointType>
 <accessPointType vendor="Aruba" model="AP-504 + AP-ANT-25A">
 <radioType technology="ax" frequencyBand="2.4" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-25A 2.4GHz 5dBi" defaultAntenna5="Aruba AP-ANT-25A 5GHz 5dBi"/>
 <radioType technology="ax" frequencyBand="5" mimo="2x2" spatialStreams="2" defaultAntenna24="Aruba AP-ANT-25A 2.4GHz 5dBi" defaultAntenna5="Aruba AP-ANT-25A 5GHz 5dBi"/>
 <radioType radioTechnology="bluetooth" frequencyBand="2.4" defaultAntennaBluetooth="Aruba AP-505 BLE"/>

Save the file.

Step 5

Open Ekahau. Now, you can find your created antenna.


You can edit the config files for APs and antennas so you can create custom AP/ANT to use in all your projects. Don't forget that you need admin rights if you want to edit anything in the folder. Also backup this file as well,this will be rewritten with the next update.


When I was working with a WLAN PI recently I stumbled upon a program named VirtualHere which allows USB devices to be used remotely over a network just as if they were locally connected. This allowed me to perform spectrum analysis remotely, both on the internal network and on a VPN connection. Actually, the options are endless and only limited to what you connect.



Server Setup:


SSH into WLAN PI

wget https://virtualhere.com/sites/default/files/usbserver/vhusbdarm64
chmod +x ./vhusbdarm64

By default, the WLAN PI blocks port 7575 used by VirtualHere.

sudo ufw allow proto tcp from any to any port 7575

to start

sudo ./vhusbdarm64

options: -b run as daemon in the background -c configuration file -h display this usage -l display license text -i prefer ipv6 (dual/stack) -r log to file instead of syslog


Client Setup:


The VirtualHere USB Client runs on Windows, OSX, Linux and Android.

And can be found here: https://www.virtualhere.com/usb_client_software


Run the client, it will automatically try to connect to the server.



Once you are connected to the server the devices attached to your USB Server are listed and you can right-click those to connect.



When you see that it is used by you, the usb is connected to your pc.





licensing

The trial version of the server will allow you to share 1 device without time restrictions using one of the generic builds needed for the WLAN PI. To share more devices you need to purchase a license.


NEVER MISS AN UPDATE

Get your name on the list.

GET IN TOUCH

We'd love to hear from you

  • Gray Twitter Icon
  • Gray LinkedIn Icon

© 2020 Wireless BLog